Modular RF Coil Array for Safe Intra-Operative DBS Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MR imaging technologies face limitations during Deep Brain Stimulation (DBS) procedures due to heating issues with DBS leads in the RF field, leading to inaccurate electrode placement and potential tissue damage, as existing head coils cannot maintain safe power levels for image quality and safety.
Innovation Solution
A modular transmit/receive RF coil array with removable elements, allowing for adjustable RF field generation and minimized Specific Absorption Rate (SAR) to accommodate intra-operative imaging, ensuring accurate placement of DBS components while preventing lead overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional head coil is used for MR imaging during DBS procedures, then imaging can be performed, but the DBS leads overheat due to RF field exposure
Solution Approach 1:
The coil array is divided into multiple individually controllable coil elements that can be selectively activated or deactivated. This segmentation allows the system to optimize RF field distribution and minimize heating in specific regions where DBS leads are located, while maintaining imaging capability in other areas.
Solution Approach 2:
The coil elements are designed with dynamic control capabilities, allowing real-time adjustment of RF transmission parameters during imaging. This dynamic control enables the system to adapt RF power levels and distribution patterns to prevent lead overheating while maintaining diagnostic image quality.
2Reliability
If the power output of the transmit coil is limited to maintain safe SAR levels, then lead heating is prevented, but image quality deteriorates
Solution Approach 1:
The system implements local quality control by applying different RF power levels to different regions of the imaging volume. Areas with DBS leads receive reduced RF power to prevent heating, while other regions maintain normal or elevated power levels to ensure adequate signal-to-noise ratio and diagnostic image quality.
Solution Approach 2:
The system dynamically changes RF transmission parameters including power levels, frequency, and pulse sequences based on the detected position of DBS leads. This parameter optimization allows the system to maintain safe SAR levels while compensating for signal loss through adjusted imaging parameters.
3Measurement precision
If the stereotactic frame and locator phantom are in place for pre-operative imaging, then accurate electrode placement can be achieved, but intra-operative imaging becomes impossible after burr-hole creation
Solution Approach 1:
The coil array is designed to function in multiple operational modes: pre-operative imaging with the stereotactic frame and locator phantom, intra-operative imaging after burr-hole creation, and post-operative imaging. The removable panel design allows the system to adapt to different procedural stages while maintaining imaging capability throughout.
Solution Approach 2:
The system performs preliminary imaging and localization before the burr-hole is created, establishing an initial reference framework. The modular coil design then allows continuation of imaging capability after the burr-hole is made, enabling real-time tracking of brain shift and verification of electrode placement without requiring repositioning of the stereotactic frame.
4Measurement precision
If all coil elements are used for imaging, then image quality is maximized, but access for stereotactic guide member is blocked
Solution Approach 1:
The coil array is segmented into multiple independent elements with at least one element designed to be removable. This segmentation allows selective removal of specific coil elements to create access pathways for stereotactic guide members and surgical instruments, while other coil elements remain in place to maintain imaging capability.
Solution Approach 2:
The coil element configuration is made dynamic, allowing elements to be added or removed based on the procedural requirements at different stages. During surgical access phases, specific elements are removed to facilitate instrument insertion; during imaging phases, elements are reinstalled or activated to restore full imaging coverage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate and safe DBS procedures by allowing for modular coil configuration adjustments, maintaining SAR below 0.1 W/kg, and ensuring precise imaging during and after burr-hole procedures, thereby reducing the risk of tissue damage.
Implementation Method 1
a plurality of coil elements each for generating an RF field; the coil elements being arranged to cooperate to generate an RF field within the head of the patient for imaging of the head
Implementation Method 2
maintaining SAR below 0.1 W/kg; ensuring accurate placement of DBS components while preventing lead overheating
Data Source
AI summary
A modular multi-transmit head coil for use in Deep Brain Stimulation procedures includes a mounting frame arranged for attachment to the stereotactic head frame of the patient. An integrated MR stereotactic locating phantom is included as part of the coil structure which has attached MR/CT compatible fiducials on it to correlate pre-op, intra-op and post op images. The frame carries a series of modular removable coil elements in a transceive array that are connected to a set of RF power amplifiers that directly drive the coil elements. A control system including suitable software is arranged to control the signals to the coil elements so as to generate a required RF field with all the coil elements in place and with one or more the coil elements removed to allow access to the patent for the installation of the DBS leads.